Yen Depreciation: Investor Miscalculations Amid Shifting Monetary Policies

Article Summary

• Analysis of why investors who bet on a rising yen lost money.
• Impact of the strong US economy on interest rate expectations.
• Role of the Bank of Japan's monetary policies in the yen's depreciation.
• Overview of currency trading strategies, such as carry trades.
• Future outlook for the yen's exchange rate against the dollar.

Investors once wagered record sums that the yen would appreciate, hoping to profit from Japan’s long-awaited economic recovery while simultaneously betting on a U.S. economic slowdown. However, reality has turned into something of a cautionary tale reminiscent of the Trump era.

The yen has slumped to a nine-month low, prompting speculators to unwind their biggest bullish bet on the currency in nearly 40 years. The miscalculation stems from two key factors: first, the unexpected resilience of the U.S. economy to trade shocks, coupled with policymakers adopting a more cautious stance on further interest rate cuts. Second, the new Japanese government's inclination to let the central bank slow the pace of interest rate hikes.

The unraveling of this prominent bet highlights how thoroughly the market has defied expectations during the first 11 months of President Trump’s second term. It also underscores the stubborn persistence of yen weakness—a costly misjudgment for investors, as holding the near-zero-yielding yen means foregoing gains achievable from other investments.

“There was a general expectation in the market that U.S.-Japan rates would converge, but that convergence may not have progressed as smoothly as anticipated,” says Bart Wakabayashi, Tokyo branch manager at State Street. He adds that his bank's clients have fully adjusted their bullish yen bets to neutral over the past seven months.

As the dollar hit a nine-month high above ¥155 this week, Japanese officials issued intervention signals, but the prevailing market view is that the currency, which has been under pressure for almost five years, is likely to trade sideways or continue to weaken.

“We are currently taking a wait-and-see approach… but are more inclined towards yen weakness,” says Vaibhav Loomba, head of foreign exchange and interest rates at Singapore-based financial services firm Klay Group. “There is a lack of definitive trading direction in the market at the moment.”

Factors Contributing to Yen Weakness

The yen's weakness is largely tied to the Bank of Japan’s cautious approach to raising interest rates, partly a response to the uncertainty stemming from U.S. tariff policies. More recently, Sanae Takaichi, who assumed the premiership in late October, has exerted further political pressure—her government is more inclined to maintain low interest rates while ramping up spending to stimulate growth.

“While her room for maneuver is extremely limited, the overall direction is certainly not yen-positive,” says James Athey, a fixed income portfolio manager at Marlborough. “At the same time, the BOJ is still standing still, constrained by fear and historical precedent.”

Japan has battled deflation for decades, and in 2024, it implemented its first interest rate hike in 17 years, but the policy rate only rose to 0.5% to avoid halting the economic recovery.

Currently, the market is simultaneously downgrading bets on future U.S. rate cuts and Japanese rate hikes, leading to a policy rate differential between the two countries of over 300 basis points, further exposing the yen to depreciation risks.

“We actually think dollar-yen could go even higher,” says Chandresh Jain, an Asia emerging market rates and FX strategist at BNP Paribas. He is betting through options that the yen exchange rate will fall below the 155 level in the coming weeks.

Carry Trades

Due to the disruption in collecting position data since September from the U.S. government shutdown, it is currently unclear whether the market has turned to net short yen positions, but the overall trend is that way. The latest available data at the end of September showed that yen long positions had more than halved since hitting a record high in April.

Option pricing also indicates that Jain's bet is gaining more acceptance.

Three-month implied volatility for dollar-yen, which measures the cost of option contracts, has fallen to its lowest level in over a year, reflecting weak demand for hedging against yen appreciation.

“It seems that the size of speculative yen short positions is not large at the moment, and we think there is room for further accumulation in the future,” says Hirofumi Suzuki, chief FX strategist at SMBC.

Admittedly, Japanese interest rates do appear to be rising, while U.S. rates are falling—a fundamental shift that leaves some bold investors still confident in the yen. But Yujiro Goto, head of Japan FX strategy at Nomura Securities, says that in the context of lenient overall financial market sentiment and low volatility, “now is definitely a time for many investors to focus on carry trades.”

Carry trades mean selling the yen.

“Our year-end forecast for dollar-yen remains at 155, but the risk of spiking to 160 in Q4 2025 has increased,” says Shusuke Yamada, a FX and rates strategist at Bank of America.